Unformatted text preview: descendents) Paraphyletic (not all descend from a common ancestor) See updated slides 15,16,17 for the pictures Shared ancestral characteristic – this characteristic or trait evolved before the clade evolved so it is shared with individuals who are not part a monophyletic clade. Shared derived characteristic – this characteristic or trait evolved when the clade evolved so it is shared with individuals. Dating fossils. Common strata layers. Dating methods – radioactive decay, magnetism of rocks Stromalites are oldest example of life – date back 3.5 Billion years...
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- Spring '08
- Evolution, common ancestor, Shared ancestral characteristic